中文摘要：

针对二维MUSIC（2D-MUSIC）估计方法实现二维波达方向估计运算量较大的问题，提出了一种基于降维MUSIC（RI）-MUSIC）的无需联合搜索与配对的估计方法．该算法利用二次优化方法将二维DOA估计分解为两级一维DOA估计，先用求根法估计信号与x轴夹角，再用最小二乘算法估计信号与y轴夹角，最后利用角度关系式得到信号的二维方向角．仿真实验表明，在信噪比较低的条件下，文中算法比2D-MUSIC算法的精度略高；在信噪比较高的条件下，两者基本相当，但文中算法具有更高的运算竦唐．

英文摘要：

According to the heavy computation of two-dimensional DOA estimation with.2D-MUSIC, this paper proposes an RD-MUSIC（Reduced-Dimension MUSIC） DOA estimation method without conjunction search or angle pairing. This algorithm decomposes two dimensional DOA estimation into two stage one dimensional DOA estimation. Firstly, we use the rooting method to estimate the angle between signal direction and x axis. Secondly, least square method is used to estimate the angle between signal direction and y axis. Finally, the 2D angle can be obtained with the angle formula. Simulation results show that the angle accuracy of RD-MUSIC is higher than that of 2D-MUSIC in the low SNR condition, and that they are equal in the high SNR condition, but RD-MUSIC has a higher operation speed.